Machines for repairing and straightening vehicle bodies such as that shown in U.S. Pat. No. 4,574,614, which is incorporated herein by reference, are in common usage today. Machines or racks of this type are particularly useful, if not necessary, for straightening unibody cars. For example, in FIGS. 2 and 10 of U.S. Pat. No. 4,574,614, tie down units (252) are shown which are bolted to a pinch welt (254) below the rocker panel of a unibody car. Since these unibody cars have no frame, it is necessary to straighten or repair teem by use of such tie down units.
In order to attach tie down units, such as units (252) as shown U.S. Pat. No. 4,574,614, one side of the vehicle must first be lifted, the tie down clamps inserted thereunder, and the vehicle then lowered down so that the weight of the vehicle is supported on the tie down brackets (252) instead of on the wheels of the vehicle.
The aforementioned installation of tie down brackets for unibody cars has heretofore been accomplished by the use of jacks, such as hydraulic or mechanical jacks. As in the use of most jacks, they are time consuming to use, and because they can slip out from under the car, they are not altogether safe. Since the use of a jack is time-consuming, inconvenient and dangerous if it slips out, it would be desirable to provide another way to lift first one side of the vehicle and then the other for the purpose of attaching tie down brackets. It is also necessary from time to time to lift up one side of the car or the other for providing access for other reconstruction purposes. This is true even for vehicles which are not of a unibody construction.